(1) Field of the Invention
The present invention relates generally to apparatus for mixing dry granular material uniformly with bulk materials, and more particularly to an improved apparatus for applying minute amounts of dry inoculant to large quantities of forage materials.
(2) Description of Related Art
Bacterial inoculant is applied to feedstuffs before ensiling, to improve the preservation efficiency of the ensiled crop. For forage crops, applying the inoculant at the cutter is the most efficacious method of application.
Inoculant can be applied in either a wet or dry condition. In a dry application, the bacteria are blended with a dry granular material and applied to the forage at the rate of ¼ pound to one pound per treated ton of forage. The most common method of application is the use of a granular applicator system such as that disclosed in U.S. Pat. No. 4,705,220. While this system clearly accomplishes its purpose of applying dry inoculant to a forage material, it has several drawbacks. First, the amounts of inoculant that must be applied require the user to handle hundreds or thousands of pounds of the materials each day. Such an amount is extremely labor intensive. However, attempts to use smaller amounts of inoculant in such a system produce variable inoculation rates, and therefore do not produce acceptable results.
Inoculants have also been applied in liquid form. Typically, dry bacterial concentrate is mixed with water and sprayed onto the forage. Application rates of one quart of liquid per ton of forage were common. As with dry applications, such large amounts of liquid products were very labor intensive.
Recently, a new applicator system that uses much less water (about 1.28 ounces per ton rather than a quart per ton) has been disclosed, in US Published Application 20030006312 to Dohrmann. While this new applicator is a vast improvement over prior art systems, there are still limitations.
First, some forage harvesters would prefer to not have to handle liquid inoculant in any manner. The difficulties and complexities of dealing with a liquid can be much greater than with a dry product.
Second, when dry bacteria are mixed with water, the inoculant must be used quickly, to maintain maximum viability. Thus, equipment breakdown, rain events, or even simply quitting for the evening, can all reduce the efficaciousness of the bacteria.